*Is it just a big coincidence* Probably. I'd check the gas cap for starters. I've heard a number of people say that their lights came on simply because it wasn't on tight enough. You might tell the guys that changed the oil your story and see if they'd take a quick look to see if they did knock a wire or hose off. Good luck.

The wiper and washer LED's flashing typically means that the AC system either has a fault, or simply needs to be retrained. The Check engine light coming on could have been simply because the instrument cluster had stopped communicating with the PCM, or it could be because the PCM detected a fault and commanded it on. The only way to know is to start by polling ALL of the vehicle modules for trouble codes, recording them and evaluating the results of the codes that were set. If the PCM did not store any codes, then the afore mentioned, loss of communication was the reason the lamp was on. Now the gages flat-lining. An instrument cluster "re-set" could do that if it was fairly quick in nature, say less than two seconds. In other words, the gages went to zero, paused, and then resumed operation. If the cluster was down longer than that it suggests again, a loss of communication between the cluster and the other modules (computers) in the car. A common reason for this is the loss of the instrument cluster ground connection because of a bad solder joint where the vehicle wiring harness connects to the cluster. This is something that MUST be proven before any repair attempt is made. A trained technician knows how to to do this. Anyone that simply starts throwing parts, such as the instrument cluster, the BCM, or the PCM is not considered a trained technician at this level. JMHO I would suggest seek out an electronics specialist in your area VIA a member search through the iATN. Here is a link that might be useful: The international Automotive Technicians Network

Auto Zone does indeed provide a readout for the "check engine" light. I stopped by there and a nice young lady, couldn't have been more than 5' tall, just right for reaching up under the dashboard without a lot of bending over. She found the connector without delay and when I said boy you knew right were to look, she said most of them are in the same place. So, I now know where the connector is, and I could feel it with my hand when I got back behind the wheel. Interesting too, for Chevy owners, on the way to Auto Zone I again had to do a hard acceleration (no wheel spinning even on wet pavement) and soon noticed that the multifunction display, above the Odometer/trip, the words "Fuel Cap" was displayed. First chance, I pulled off the road and checked the fuel cap. It felt loose, so I took it off and put it back. It is a flaky cap in my view, one can put the cap in and turn it to the "click" position and still the cap isn't on. I think that might be what happened and the acceleration shook it loose. Anyway, the AZ person said the code was for fuel system ventilation (I don't recall now exactly what she said). We looked and they had a replacement cap, but I said I'll check the cap I have out more before replacing it. She said the check light would not go out for a "while".. maybe until I refuel or just drive "far enough". The check symbol is still lighted, but the display no longer indicates "Fuel Cap"

You and the shop have both ventured down a path you should not have taken. If the shop really knew as much as they should about today's computer controlled cars, they would not have advised you to just keep running it, because if the check engine light is on, it basically means the car's computer has detected a problem where the car is probably polluting the air more than 1.5 times (or more) than the FTP limits. The fact that you have a different air cleaner, and exhaust all by themselves didn't cause that to happen directly. But I can tell you, I'd probably look at your vehicles situation, perform some base investigating of the failure, then the odds would be high that I would turn you down as a customer. It's one thing to fix a broken car, one that has a natural failure from it's base design. But repairing one that is altered simply has too many variables to allow for any normal diagnostic path. Simply said, the Lexus service manual does not have any segments that say with code P0XXX perform this set of tests, and with code P0XXX and this vehicle modification(s)perform another set of tests.